The instant invention relates to employment of a tough wear resistant resilient substance for use as a covering material on the rollers of a roller conveyor to dampen operational noise levels as well as to substantially reduce nicking and marring of the coating and finish on conveyed product, in addition to providing an economical and efficient means and method for on site fabricatingly installing replacements of worn or damaged roller covers when the need arises. In particular, the substance used as roller sleeve replacement material herein is weldable urethane sheet, and the type roll conveyors involved are those typically employed in moving steel reinforcing bars and rods into and out of a cutting station on a shear line.
Characteristically, the conveyancing machinery employed in a reinforcing bar shearing line operation, for both input and output transport of reinforcing bar material to and from the cutting station, employ bare steel rollers which contribute to the creation of extremely high metal-to-metal noise levels during conveyancing, in addition to nicking and damaging the reinforcing bar rust-inhibiting protective epoxy coating during conveyancing.
Past use of resilient plastic and rubber materials for reinforcing bar conveyor roller covering to reduce noise levels and epoxy coating nicking has been unsatisfactory with respect to two factors, first the time and cost of removing the roller form a conveyor frame to effect recoating the thereafter the additional time and cost to reinstall the rollers, and second the relatively short wear life of such coatings due primarily to the fact they were bonded to the supporting roller core which did not then allow for rotational slippage of the covering thereon and thereby did not enable rotational displacement absorption of high impact shocks from forward moving pieces of reinforcing bar during conveying, which would result in gouging in the pliable roller sleeve thereby contributing to accellerated wear and shortened life of the roller covering. Teachings which exemplify the core-bonded cushioned roller sleeve structures are those as respectively set forth in U.S. Pat. No. 4,312,444 to Mushovic dated Jan. 26, 1982, and U.S. Pat. No. 4,864,704 to Hogan et al dated Sep. 12, 1989.
A prior art teaching owned by Assignee herein, which obviated both the foregoing problems, was as set forth in U.S. Pat. No. 4,926,995 to Kauffman, dated May 22, 1990, which was for a separable roller sleeve having the features of being easily and quickly installed upon a conveyor roller without removal thereof, and also being slightly oversized to allow for the rotational displacement absorption of high impact shocks form forward moving pieces of reinforcing bar during conveying. Under most roller conveyor replacement sleeve applications the Kauffman separable roller sleeve proves fully adequate and satisfactory, however, in some instances where there are large conveyor rollers (those having diameters of say six-inches or greater), or the operational conditions such as conveyor speed or conveyed product load density would warrant it, a connected replacement roller sleeve has proven to work more satisfactorily.
The applicant herein, by his weldable roller sleeve invention, retains the efficiency and economy of accomplishing replacement sleeve installation on site without having to remove rollers from the conveyor and retains the replacement sleeve oversize rotational slippage feature to enhance wear life as obtained with the separable roller sleeve, in addition to providing a connected replacement roller sleeve capability for all applications, regardless of roller size and operational conditions, and especially those roller sleeve replacement applications where the roller size or operational conditions are such as to otherwise render employment of a separable sleeve replacement less than fully satisfactory.